The victims died in explosions and gunfire during attacks authorities blamed on the Boko Haram Islamic sect fighting to overthrow the government, the BBC reported Friday.
Police said they recovered four AK-47 machine guns and a motorcycle when the arrests were made.
Boko Haram followers have claimed responsibility for the deaths of dozens of police officers and politicians during the past year. Last week, a Boko Haram representative told the BBC the sect carried out a series of bombings after President Goodluck Jonathan's inauguration.
A spokesman said Boko Haram also was responsible killing the brother of the Shehu of Borno, one of Nigeria's most important Islamic leaders.